xref: /third_party/curl/docs/examples/localport.c (revision 13498266)
1/***************************************************************************
2 *                                  _   _ ____  _
3 *  Project                     ___| | | |  _ \| |
4 *                             / __| | | | |_) | |
5 *                            | (__| |_| |  _ <| |___
6 *                             \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at https://curl.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 * SPDX-License-Identifier: curl
22 *
23 ***************************************************************************/
24/* <DESC>
25 * Use CURLOPT_LOCALPORT to control local port number
26 * </DESC>
27 */
28#include <stdio.h>
29#include <curl/curl.h>
30
31int main(void)
32{
33  CURL *curl;
34  CURLcode res = CURLE_OK;
35
36  curl = curl_easy_init();
37  if(curl) {
38    /* Try to use a local port number between 20000-20009 */
39    curl_easy_setopt(curl, CURLOPT_LOCALPORT, 20000L);
40    /* 10 means number of attempts, which starts with the number set in
41       CURLOPT_LOCALPORT. The lowe value set, the smaller the change it will
42       work. */
43    curl_easy_setopt(curl, CURLOPT_LOCALPORTRANGE, 10L);
44    curl_easy_setopt(curl, CURLOPT_URL, "https://curl.se/");
45
46    res = curl_easy_perform(curl);
47
48    /* always cleanup */
49    curl_easy_cleanup(curl);
50  }
51
52  return (int)res;
53}
54